Electric alarm system.



A. U. & S. E. WEAVER.

ELECTRIC ALARM SYSTEM.

APPLICATION FILED r2113. 1912.

Patented Feb. 11, 1913.

2 SHEETS-*SHEET 1.

In ventors Attorneys A. U. &-S. B. WEAVER.

ELECTRIC ALARM SYSTEM.

APPLICATION FILED FEB.3, 1912.

Patented Feb. 11, 1913 2 SHEETS-SHEET 2.

: ia 6, i Inventors Attorneys U "TED STATES PATENT OFFICE.

ALLISON. U. WEAVER AND SPENCER E. WEAVER, OI SANTA ANNA, TEXAS.

' ELECTRIC ALARM SYSTEM.

Specification of Letters Patent.

Patented Feb. 11, 1913.

' Application filed February 3, 1912. Serial No. 675,194.

To all whom it may concern:

Be it known that we,

the county of Coleman, State of Texas, have invented a new and useful Electric Alarm System, of which the following is a specification. I j The present invention relates to improvements in electrical alarm signals, the present invention being especially adapted for use in connection with the detection of a fire and the operation of a fire alarm, a novel form of circuit closing means being provided in the form ofa selenium cell so disposed with a refiecting'and refracting medium, that-the rays of light due to the fire are projected upon such selenium cell, so as .to render the same a conductor of electricity and thereby close an alarm circuit or an alarm controlling-circuit to actuate an alarm. v

A further object of the present inventionis the novel constructionof a light reflecting.

and refracting member which has disposed therein and suspended centrally of the lon-' itudinal length of said member and concentrically with relation to the cross sectional area, a selenium cell, such cell being connected in an operatmg c rcuit, while at one end such member 1s provided with a magnifying reflector, and with a lens disposed in.

the opposite end, the inner walls of such member being further provided with a -refiecting'surface, whereby the entrance of the rays of light through the lens will be reflected or refracted upon the selenium cell to render thesame a conductor of electricity.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the com bination and arrangement of parts and in the details of construction hereinafter descril l and claimed, it being understood that changes in the precise embodiment of invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawingsFigure 1isa diagrammatic view with this novel form of circuit ALLISON U. WEAvER- and SPENCER E. WEAVER, citizens of the "United States, residing at Santa Anna, 1n

closer used in connection with a power cir- .tudinal".sectional view-through the circuit closing mechanism. Fig. 4; is a section taken on line 4L4 of Fig. 4; Fig. ,5 is. a detail View illustrating the action and direction of pro ection of the rays of light through the lens and upon the interior surface and reflector'or mirror of the circuit closer and the selenium cell.

Referring to the drawings, and more particularly to Fig. 1 thereof, the numeral 1 designates the generator which has led thereaway from the conductor 2 which is connected to a metal conductor 3 insulated by means of the bushing31 and carrying the selenium cell 4 within thecylinder 18. Leading away from said conductor 3 from the opposite end thereof is a conductor 5 connected toa rheostat 6, another conductor 7 being led away from the rheostat to an electromagnet 8, which is connected to the other side of the generator 1 by means of the conductor 9. In the diagram as shown in Fig. 2, the battery source 1 and a manual switch 6 is employed in lieu of the generator 1 and rheostat 6. In both of these diagrams, the. armature 10 forms the switch for an alarm circuit, the same being normally held open by means of the spring 11.

When. the control circuit containing the seleniumcell 4 is closed, due to the effect of light upon the selenium cell, the electromagnet 8 is energized and attracts the armature 10, which in turn engages the contact point 12, and thus closesa circuit through the conductor 13, audible alarm 14, conductor 15, batteries 16 and conductor 17 which is connected to the armature 10. By thismeans it will-be seen that an alarm is given, due to the efi'ect of light upon the selenium cell, thus closing the control circuit, and that by reason of the rheostat 6 or the switch 6', the

said control circuit including the selenium cell will be cut out during the daytime so that a false alarmwill not be given.

The main controlling circuit closing demounted at one end thereof, the" lens 19,

' light, the rheostat .or switch is cut ofl", but

vice as clearly shown in Figs. 3, 4 and 5 consists of a cylindrical member 18 having while disposed at the opposite end thereof is "a mirror 20, the same being formed concaved with the concavityopen to the interior of saidcylinder 18. The walls 21 of said cylinder are also coated with a reflecting ma'- terial, while the conductor rod 3 carrying the selenium cell 4 and-insulated from the cylinder 18 by means of the bushings 31., is

so disposed as to be in the longitudinal center of the cylinder 18 and forming a diameter of the circle formed by the walls of said cylinder, the selenium cell 4 being disposed centrally of said rod so as to be in the exact center, both longitudinally and transversely of the. cylinder 18.

From the foregoingdescription taken in connection with the drawings, it is evident that when the rheostat 6 and the switch 6 is closed, and no rays of light are penetrating the lens to the interior of the cylinder 18, that the selenium cell is 'not affected and But.

that such controlling circuit is open. for instance, however, as illustrated in Fig. 5, a light be so disposed in front of the lens and in sucha way as to have itsrays projected by such lens'into the interior of the cylinder 18, the rays of lighttherefrom will be reflected and refracted as clearly illus-' trated by the dotted lines and arrows Fig. 5, so as to be finally projected upon either and both sides of and against the selenium cell 4, thus rendering the cell a good conductor of electricity and closing the controlling circuit and energizing'the electromagnet 8 as before described.

As before stated during the day time when the selenium cell might be affected by where the device is used in. cellars or dark rooms, the said rheostat or switch may be closed at all times, so that the controlling circuit will be closed due to the rays of lightcaus'ed by a fire.

In practice it has been found that a very dim light, or rays therefrom that would not ordinarily affect the selenium cell, is ef-.

fected and magnifiedby the convex lens, the

concaved mirror and the polished walls of cell without a cylinder as herein set forth,

are so reflected as to affect. the cell and concuit therefor, a selenium cell in said. circuit,

a confining tube for said cell, a lens mounted in one end of said tube, and means carried by said tube for reflecting the rays of "light permeable to the lens upon the selenium cell to close the control circuit.

3. In an electric alarm, a normally open alarm circuit, a normally open control circuit therefor, a seleniumcell in said circuit, a confining-tube for said cell, a lens mounted in one end ofsaid tube, the inner walls of said tube being a reflecting surface,- and a mirror disposed at the opposite end to the lens for ,coaction with the reflecting walls of the tube to direct therays of light entering the tube upon the selenium cell to close the circuit.

4'. In an electric alarm, a normally 0 en alarm circuit, a normally open controlllng circuit therefor, a light confining tube, a selenium cell disposed at the longitudinal and axial center of said tube and insaid contro'lling circuit, a lens mounted in the entrance end of said tube, the interior of said tube being a reflecting surface, and a reflecting medium carried in the opposite end of said tube for coacting with the reflecting surface of the tube to direct the rays.

of light entering through the lens upon .the

selenium cell.

' 5. A selenium cell circuit closing medium,

having a cylindrical tube, the. inner surface of which is a reflecting surface, a conducting rod disposed diametrically of said tube at the longitudinal central point thereof,- said rod being insulated from the tube, a

selenium. cell' disposed axially of the tube and carried by said rod, and a reflecting medium carried in one end of said tube for coaction with the reflecting interior walls thereof to direct the rays of light entering.

' the tube upon the selenium cell.

' 6. A selenium cell circuit closing medium, having a cylindrical tube, the inner surface of which is arefiect'ing surface, a conducting rod disposed diametrically of said tube at the longitudinal central point thereof, said rod being insulated from the tube, a selenium cell disposed-axially of the tube and carried by said rod, a reflecting mediumcarried in one end of said tube for coaction with the reflecting interior walls thereof to direct the as our own, we have hereto alfixed our sigrays of light entering the tube upon the natures in the presence oftwo witnesses.

selenium cell, and ,a lens disposed in the ALLISON U. WEAVER.

opposite end of said tube for magnifying SPENCER E. WEAVER. 5 the light ray efiect upon the reflecting sur- Witnesses:

faces Within the tube. LEON -L. SHIELD,

In testimony that we claim the foregoing FRED W. TURNER. 

